DOGE and PEPE are real memes that existed before crypto and will continue to exist. There is no reason why it would lose its follow especially when it has established itself so well. SHIBA is another subject. Still this does not mean that they will be as relevant as they are today as the market caps of all major coins continues to increase.
They will. These are established memecoin projects that have existed throughout the bear market and they're still valued significantly higher than infrastructure projects in crypto. For example, EigenLayer with over $12B in TVL was valued < $1.5B FDV while all of the aforementioned memecoins were worth several billions.
Yes, because EigenLayer is just another of many projects of the same kind. People are bored of infrastructure projects, there are too many. Meanwhile DOGE and PEPE are unique memes with unique cultures and many followers.